Many refrigerators and freezers have an interior light that is off when the door is closed, but is on when the door is opened. To turn such a light on or off in response to the movement of the door, a normally-closed switch is commonly installed near the door of the refrigerator or freezer. Such a normally-closed switch has a push button that is biased into an extended position. When the push button is in this extended position (i.e., when the door is open), a moveable terminal is in contact with a stationary terminal, completing a circuit that energizes the interior light. As the door is closed, the push button is engaged by the door and rotates into the housing of the switch. Such rotation of the push button causes an internal post member to move downward and apply pressure to the moveable terminal, causing the moveable terminal to break contact with the stationary terminal, thus opening the circuit.
One problem that commonly occurs with such normally-closed switches is that, in some cases, the circuit never opens, and the interior light is always on. For instance, improper installation of the switch can lead to this problem, especially when there is a lack of quality control by the manufacturer with respect to ensuring the correct gap between the liner and the door relative to the switch location. Further compounding this problem, when the internal post member moves downward and causes the moveable terminal to break contact with the stationary terminal, it has also been observed that there is often some slight movement of the stationary terminal. In other words, the stationary terminal may move with the moveable terminal to some extent, resisting the disengagement of the moveable terminal from the stationary terminal.
Thus, there remains a need for an improved construction for such a normally-closed switch that better ensures that the circuit is opened (and the interior light off) when the door is closed.